Equine Nutrition

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Equine Nutrition Feeding
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Time-Budgets

• Feral Horses
• Select highest fiber, lowest protein content
• 70 of its day foraging
• Stabled Horses
• 10 of their day feeding
• Meal fed

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Mastication

• Jaw sweeps 60,000 times/day when grazing
• Saliva contains little, if any amylase

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Digestion is organ specific
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Amino acids and fat digested and absorbed in
small intestine Vitamins/minerals absorbed in
small intestine
Starch digestion occurs in the stomach and small
intestines (Stomach 15 min. Small intestine
30-90 min.)
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Fiber digestion occurs in the cecum/colon (48-72
hours)
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Digestive Tract

• Stomach
• 9-15 liters
• Trickle feeders
• Transit time lt2 hr
• Cardiac sphincter does not relax to allow
  regurgitation

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Digestive Tract

• Small Intestine
• 30 of digestive tract
• 40-50 liters
• Transit time 45 min to 8 hrs
• a-Amylase low varies widely between horses
• Starch digestion occurs in the stomach and small
  intestines
• Amino acids and fat digested and absorbed in
  small intestine
• Vitamins/minerals absorbed in small intestine

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Digestive Tract

• Hindgut 60 of digestive tract capacity
• Cecum
• 25-35 liters
• Transit time lt 5 hr
• Large Colon
• 50-60 liters
• Small Colon
• 18-19 liters
• Large small colon transit time 36-48 hrs
• Fiber digesters most active pH of 6.2-6.8
• Starch digesters prefer pH 5.2 6.0

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Microbial Fermentation
Microbe
Fibrous Non-Fibrous Carbohydrate
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Aspects of The Foal GI Tract

• Small digestive tract
• The small intestine does not increase in length
  from 4 wks of age
• Cecum not fully functional until 15-24 mo of age
• The large intestine increases with age even up to
  20 yrs

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Carbohydrates
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Postprandial Cecal pH Change
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How hindgut acidosis can occur in hindgut and how
it can be attenuated
Pagan, J. 2007. Feedstuffs
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Same DE in each sample, take a look at the amount
of starch though!
Corn 4.3 2.71
Oats 5.0 1.82
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Starch Comparisons (whats low, whats high)
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Starch Digestion

• Critical capacity for hydrolysable carbohydrate
  overload 0.4 of BW
• Maximizing starch digestion in small intestine
• Properties of the starch granule
• Grain processing
• Plant cell walls
• Transit time through the small intestine
• Availability concentration of enzymes

Cuddeford, D. 1999 Harris et al. 1999
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REMEMBER!

• The number one cause of deaths from colic is
  from starch overload due to feeding
  mismanagement.

Dr. John Reagor, PhD Chief of Toxicology Texas
Veterinary Medical Diagnostic Laboratory
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Glycemic Response

• Hyperglycemia occurs after digestion of grain
  meals
• Affects substrates utilized during exercise

• Glucose insulin peak 60-90 min after a meal
• Insulin promotes fat storage
• Sugary meals before exercise will ? CHO to muscle
  ? fat oxidation

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Feeding Horses

• Feed intake usually expressed as
• of Body Weight
• Lbs feed/100 lbs body weight
• Free Choice
• Min. 1 BW as forage

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Building a Horse Ration

• Start with horse needs
• Maximize forage
• Add energy if needed
• Add protein minerals if needed
• Consider adding vitamins supplements
• Consistency is key to good feeding practices

Feed concentrate that makes-up the difference
between nutrients needed nutrients in roughage
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Forages are the FoundationPasture, Hay

• Grass
• Bromegrass
• Orchardgrass
• Tall Fescue
• Timothy
• Grain Hay
• Oat Hay
• Wheat hay
• Straw

• Legume
• Alfalfa
• Birds Foot trefoil
• Clovers
• Lespedeza

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Ingredients Used In Place of Hay for Roughage

• Good Quality Sources
• Beet Pulp
• Soybean Hulls
• Dried Citrus Pulp
• Dried Apple Pectin Pulp
• Alfalfa Meal

• Poor Quality Sources
• Peanut Hulls
• Oat Hulls
• Ground Straw
• Cottonseed Hulls
• Rice Hulls
• Rice Mill Feed

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Forage Isnt Everything

• Most do not have all the minerals /or vitamins a
  horse requires. Four ways to add these.
• Add 1 to 4 oz mineral or mineral/vitamin
  supplement per day or
• Add 1 to 2 lbs ration balancer (mineral plus
  protein) per day or
• Feed 5 to 7 lbs fortified grain per day or
• Feed 12 14 lbs complete feed (forage grain)

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Energy Sources - Grains

• Oats
• variable
• crimped vs. whole
• Corn
• cracked, steam rolled

• Barley
• Sorghum wheat
• less than 30
• rolled, cracked, flaked,

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Fat/Fatty Acids

• No gall bladder
• Horses can be safely fed up to 20 fat in the
  total diet
• Energy from fat is 90 utilizable
• Often used to supplement calories for
  hard-working horses and hard keepers
• Reduction in DM intake bowel weight
• Calmer temperament

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Protein

• Muscle bone growth, milk production, fetal
  growth, normal metabolism
• Requirements can be met with good quality hay or
  pasture forage
• Low requirements for maintenance
• Quality amino acid balance
• Very important for young horses
• Lysine, methionine, tryptophan most limiting for
  growth milk production

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Sources of Protein for Horses

• Soybean Oil Meal
• Flax - Linseed Meal
• Sunflower Meal
• Cottonseed Meal
• Peanut Meal
• Corn Gluten Meal

• Whey
• Dried Skim Milk

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Minerals

• Content in the diet
• Determined by soil water
• Quality of feed proportion of grain to hay
• Macro-minerals
• Ca P - quality forages usually provide adequate
  amount
• This ratio is very important 1.51 to 21
• Grains are rich in P and low in Ca
• NaCl (Salt)
• Salt block will meet many horses needs
• If horses sweat a lot - need salt in the ration
• Trace Minerals
• Look for iron, zinc, copper, selenium

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Minerals

• Macro-minerals
• Ca P - quality forages usually provide adequate
  amount
• This ratio is very important 1.51 to 21
• Grains are rich in P and low in Ca
• NaCl (Salt)
• Salt block will meet many horses needs
• If horses sweat a lot - need salt in the ration
• Trace Minerals
• Look for iron, zinc, copper, selenium

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A guide to the recommended concentrations of
trace elements in the diet, mg/kg dry matter.
(Modified fromthe NRC 2007). These will need to
be adjusted to suit individual circumstances,
growth rate and appetite etc.
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Vitamins

• Fat soluble
• stored in body - A, D, E, K
• Toxicitys can occur if fed in excess
• Water soluble
• must be continuously supplied
• B-complex niacin, thiamin, riboflavin

• High quality fresh forages maintenance for
  mature horses
• Hay is poor in Vit A, supplement Vit A in the
  ration
• Exposure to sunlight provides Vit D
• Supplement Vitamin E

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Guide to recommended levels of Fat-soluble
vitamins (need to be adjusted according to
individualcircumstances).
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Water

• Essential for all body functions
• Temperature regulation
• Feed digestion
• Amount of water intake
• Level of exercise
• Ambient temperature
• Quality of feeds in ration
• Proportion of diet that is forage
• Minimum 1 gallon/100 lbs BW/day

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Maintenance

• Size body weight
• Environment
• Individual differences
• Dry matter intake 1.5 of the BW
• Most - energy requirements are met with forage
  alone

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Recommended Daily Feed Intakes as of Body
Weights
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Geriatric Horses

• Nutrient Considerations
• Reduced salivation
• CF digestibility ?
• Total fiber lt 30
• CP digestibility ?
• 10-14 CP
• Energy
• Increase soluble carbohydrates, fats, oils
• Caloric Restrictions
• Supplement minerals vitamins including vitamin C

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Selection of Feed For the Geriatric Horse
28 yr old horse

• Highly palatable
• Easy to chew swallow
• Forage - chopped, cubed, pelletized, or in a
  wafer
• Grains - rolled, crimped, or flaked

32 yr old horse
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Feeding The Athlete
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Aerobic and Anaerobic Metabolism

• During exercise, ATP is generated from breakdown
  of
• Glucose
• Fatty acids
• Amino acids
• ATP low in muscles essentially no storage
• Continuous ATP production vital for athletes

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Simplified Energy for Muscle Contraction
Blood Glucose
Free Fatty Acids
Lipolysis
Muscle Glycogen
Oxidative Metabolism
Pyruvate
Lactate
ATP
Creatine Phosphate
CO2and Water
O2
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Work

• ENERGY, ENERGY, ENERGY
• Electrolytes water ? muscle function and fluid
  balance
• Forage is not enough for 1 hour/d moderate work.
  Starch is necessary for replacing glycogen stores.

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Levels of Performance/Work

• Light Recreational riding, beginning of
  training programs, Show horses (occasional)
• Moderate School horses, Recreational riding,
  Show horses (frequent), Polo, Ranch
• Heavy Ranch, Polo, Show horses (frequent,
  strenuous events), Low-medium eventing, Race
  training (middle stages)
• Very Heavy Racing, Elite 3-day event

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Performance/Work

• Energy

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Feeding Guidelines for Performance Horses

• Starch is necessary for replacing glycogen
  stores.
• Hay
• Feed at least 50 of total ration as forage
  (pasture /or hay)
• Preferably high quality grass hay or
  alfalfa/grass mix
• Exercising horses do not need high levels of
  protein
• More important quality of protein
• Horses should be fed to meet their immediate
  needs
• Cut grain on rest days

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FAT SUPPLEMENTATION

• Enhanced stamina
• ? capacity for uptake oxidation of fatty acids
  in muscle
• Concomitant decrease in use of endogenous
  carbohydrate stores - Muscle glycogen sparing

Add 6-10 weeks before performance
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Feeding Guidelines for Performance Horses

• Hay requirement
• Feed at least 50 of total ration as forage
  (pasture /or hay)
• Preferably high quality grass hay or
  alfalfa/grass mix
• Exercising horses do not need high levels of
  protein
• More important quality of protein
• Horses should be fed to meet their immediate
  needs
• Cut grain on rest days

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Breeding Animals

• Maiden mare
• Barren mare
• Flushing- Increasing energy intake 20-25 3 wks
  prior to breeding.
• Gestating mare
• Lactating mare
• Stallion

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Gestating Mares

• Last 3 month of gestation 60 foals weight
• Mare needs to gain 0.3 0.8 lb/d

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Lactating Mare
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Lactating Mare

• Month 1 3
• milk is 3 BW
• Month 4 6
• milk is 2 BW
• Requirements of energy, protein, mineral, and
  vitamin double vs. maintenance

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Feed Consumption ( BW)

• Adding concentrate to late pregnancy mares
  accounts for limited energy acclimates microbes
• Allow 1 wk to 10 d for mares to adjust to intake
  changes
• Heavy milkers may require as much as 1.75-2.0 of
  BW in concentrate feed/day

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Body Condition Score

• Reason Standardized scale for estimating and
  comparing body fat
• Developed in 1983 by Dr. Don Henneke
• System for assessing subcutaneous fat
• Nine levels of body condition
• Six body areas of fat storage
• Uses
• Research
• Feed management
• Health management

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Body Condition Scoring

• 1-3 Poor-Thin
• 4 Can see ribs, vertebra ridge evident
• 5 Back flat, cant see ribs, but can feel
  them
• 6 Crease down back, fat deposits
• 7-9 Fleshy - Extremely fat

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Time Additional Grain Required To Improve BCS
by 1 level
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Body Condition Score

• Maximum Reproductive Efficiency
• Moderately fleshy to fat mares can be expected to
• Cycle earlier in the year
• Have fewer cycles per conception
• Have a higher pregnancy rate
• Maintain pregnancy more easily
• Mare prior to breeding should have a BCS of 6 or
  greater and fed to maintain weight.
• BCS of 5.0 is marginal especially for lactating
  mare.

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Feeding The Growing Horse

• Goals
• Maximize genetic potential for growth
• Sound musculoskeletal system

• Nutrient Balance is important
• Requires higher quality feeds
• Growth rate age determines requirements
• Growing till reach 30 months

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Average Daily Gain
Avg. Daily Gain, lbs/d
Month of Age
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Nutritional Strategies Aimed at Minimizing DOD
Rations should be balanced to promote a
consistent growth curve
www.Foalcare.com
Requires periodic updating of the ration
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Nutritional Strategies Aimed at Minimizing DOD

• Feed selection
• High quality forage is a must
• Grain mix concentrates formulated specifically
  for growing horses
• Improper use of supplements
• Feed amounts
• Forage
• Minimum of 1 lb / 100 lb BW / d
• Fed to appetite is best
• Concentrate
• 1 lb / 100 lb BW / d
• Max. 8 to 10 lbs /d

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Monitor The Growth Process

• Daily Intakes
• Body Weight
• Average daily gain
• Signs of Skeletal Abnormalities
• Physitis
• Joint effusion
• Lameness

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Feeding Guidelines Strategies To Minimize Risk
Of Hind Gut Dysfunction

• Consider..
• Body condition
• Stage of production
• Quality of feeds available

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Feeding Guidelines Strategies To Minimize Risk
Of Hind Gut Dysfunction

• Check for Refusals
• Change type amount of feed gradually. 7-10 d
  period
• Provide Salt

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Feeding Guidelines Strategies To Minimize Risk
Of Hind Gut Dysfunction

• Control amount of NSC (sugar, starch fructan)
  the horse consumes.
• Minimize the flow of fermentable polysaccharide
  to the large intestine
• Feed starch sources little and often i.e., less
  than 5g oats/(2g starch)/kg body weight/meal
• Pre-feed forages

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Feeding Guidelines Strategies To Minimize Risk
Of Hind Gut Dysfunction

• Minimize the flow of fermentable polysaccharide
  to the large intestine
• Limit rate of concentrate intake through physical
  obstruction
• Maximize substrate (glucose) availability to the
  performance horse
• Ensure good occlusion of teeth through regular
  dentistry

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Feeding Guidelines Strategies To Minimize Risk
Of Hind Gut Dysfunction

• Group Feeding Should Account for Dominance
  Hierarchies
• Recognize Feeding-Related Behavior Problems

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